Run the following command, after reading the notes below:
sfdisk -d /dev/sda | sfdisk /dev/sdb
Notes:
1. This copies the parition information of sda to sdb. Be very careful with the drive letters, otherwise you might end up overriding the partition of a good drive with the partition from a new drive.
2. sda is the drive from which .... Source article on Gaea Times at : How to parition a new drive before adding to RAID array in Linux.